Call transmitter



Jan. 8, 1946. R, CROCKER 2,392,726

CALL TRANSMITTER Filed Oct. 17, 1941 INVENTOR. BY Raoh Cracker AttorneysPatented Jan. 8, 1946 UNITED STATES PATENT OFFICE CALL TRANSMITTER RalphCrocker, Swampscott, Mass.

Application October 17, 1941, Serial No. 415,336

7 Claims.

The present invention relates to call transmitters and more particularlyto units for operating the finger wheels of telephone call transmitters.

It is an object of the present invention to provide a call transmitterof the key controlled type which is of improved construction andarrangement and which is thoroughly reliable in operation.

Another object of the invention is to provide a unit for operating thefinger wheel of'a telephone call transmitter which may be readilyattached to the associated telephone set.

The invention, both as to its organization and method of operation,together with further objects and advantages thereof, will best beunderstood by reference to the following specification taken inconnection with the accompanying drawing, in which Figure 1 is a sideelevational view of a telephone set supporting a call transmitterembodying the present invention; Fig. 2 is a face view of the dial plateof the call transmitter; Fig. 3 is an enlarged side elevational view ofone of the digit keyscarried by the dial plate shown in Fig. 2,illustrating the operated position thereof; and Fig. 4 is an enlargedside elevational view of the digit key shown in Fig. 3, illustrating thereleased position thereof.

Referring now more particularly to the drawing, there isillustrated aconventional telephone set-l of the desk type carrying a conventionalcall transmitter II on the front of the base or pedestal thereof, thecall transmitter l l comprising a casing 12, housing the usual impulsetransmitting mechanism, and a finger wheel [3 secured to a rotatablearbor 14 extending into the casing 12 and forming a part of the impulsetransmitting mechanism. Also, there is illustrated a unit 20 embodyingthe present invention which operates the finger wheel [3 of the calltransmitter ll The unit 20 comprises a supporting standard 2| which isdetachably secured to the telephone set It! justabove the pedestal andjust below the cradle thereof by a clamping arrangement including twoscrews 22'. The standard 2| supports an electric motor 22 disposeddirectly in front of and in spaced relation with respect to the fingerwheel I3 of the call transmitter ll. Preferably, the electric motor 22is of the single phase, constant speed, synchronous type of conventionalconstruction and arrangement, and is provided with an operating circuitincluding a source of single phase alternating current of commercialfrequency, not shown, and a control switch 23 of the snap action type.More particularly, the electric motor 22 comprises a casing 24, housingthe usual motor elements and speed reduction gearing, not shown, and anoperating shaft 25 which projects through the casing 24. The casing 24of the electric motor 22 is secured to the standard 2| by an arrangementcomprising a screw 26 and a plate 21 directly carried by the casing 24.

Also, the unit comprises a substantially U- shaped bracket member 28provided with two substantially parallel spaced-apart arms 29 and 30.The arm 29 of the bracket 28 is secured directly to the finger wheel 13and the arbor I4 of the call transmitter II. More particularly, thelower surface of the arm 29 carries two projections 3| which arereceived in two of the finger openings provided in the finger wheel l3of the call transmitter ll. Also, the arm 29 has an opening formedtherein which receives the outer end of the arbor M of the calltransmitter II, a nut 32 being threaded on the outer end of the arbor I4in order to retain the arm 29 securely clamped in its adjusted positionwith reference to the finger wheel I3and the arbor l4 of the calltransmitter H,

' The arm of the bracket 28 carries a dial plate or disk 33 arrangedabove and in spaced relation with respect to the casing 24 of theelectric motor 22, the dial plate 33 being secured to the outer surfaceof the arm 30 by an arrangement comprising a screw 34. The outer end ofthe operating shaft 25 of the electric motor 22 has secured thereto agear 35 which is arranged below and in spaced relation with respect tothe dial plate 33. The arbor M of the call transmitter H, the operatingshaft 25 of the electric motor 22 and the center of the dial plate 33are arranged in alignment along a common center line, for a purpose morefully explained hereinafter. v

The dial plate 33 has ten circular holes 34 formed therein adjacent theperiphery thereof, the holes 34 being equally spaced apart about a majorportion of the circumference of the dial plate 33 and disposed in anannular row. Adjacent each of the holes 34 and disposed inwardly withrespect thereto, the dial plate 33 carries the usual indicia in the formof the numerals I, 2, 3, etc., and the letters ABC, DEF, GHI, etc., inaccordance with conventional practice. the dial plate 33 carries tendigit keys IK to 0K, inclusivejwhich respectively cooperate with the tenholes 34 formed therein. a

Preferably, each of the digit keys IK, etc., is of conventionalrocking-bar over-center toggle construction. For example, the digit keyIK comprises a rocking bar 36 pivotally mounted on Further,

.the rocking bar 33 comprises an; operating projection or tab 40disposed on one end thereof and a releasing projection or tab 4|disposed on the opposite end thereof.

It will be readily understood that when the elevatedoperating tab 40 isdepressed'the rocking bar 36 is rotated in a clockwise direction 7,

about the cotter key 31 in order to cause the releasing tab 4| to beelevated and the" toggle arm 39 to b oscillated about its pivot towardthe ear 35, the elements mentioned being "moved from thepositionsshow'rrin Fig; 4 to the'positions Shaw-h 3 with a shap' action;1 on the "other h'arfd,"wheir the elevatedreleasin'g' tab 4| is de-'rssedthe" rockingb'ar'flfi isrdtated in a counterclockwise dire'ctionabout the cotter key 31 in order 'tobause the operatingtab 40 tobe'elevated the toggle arm 39'to"beosci1latedabouti'its pivotaway fromthe gear 35, the elements 'men ti'oned lbeing moved' "from" thepositions shown in 31othepositions'shown in Fig. 4 with a'snap action.The 'lower'endofthe toggle arm 39 carribs projection "42' which adaptedto engage and disengage the teethprovided; on the periphery of "the gearf-3 5 when the toggldarr'ri' occupies its respective" positionsshownin"Figs. 3 and 4. Accordingly,it will beunders'tood-that when theelevatedoperatirfg' tab w'of any' one of the digit kys-'- IK; 'etc.,""is"depressed the" releasing tab 4| thereof is elevated "and the toggle"arm 39- thereof isoscillat'edabout itspivot in order to movethe'projection- "42' into engagement with" the t'eeth' provided about theperiphery of the gear' 35, wherebythe dial plate '33 is clutched to thegear 35 ;P *on the? other "hand;"when" the 'elevated 're leasing taib 4|of anywne'of'the digit keys I K, etcl i'si-depressed theoperating' tab40 thereof is elevatedand the toggle arm 39 thereof is 'oscillate'd'ab'out its? pivot in order "to move the pro jebtion" "42 out ofengagement "with' the teeth provided? about the periphery of the 'gear35; wherebyrthedial plate '33 is declutche'd' from the ear:35, i v

"fll inally, the unit 20 comprises a substantially U-sh'a'ped rela'singelment43' provided with two substantially parallel spaced-apart arms 44'and 45:?1'Th'e"arrn 44 o 1'tlie "re1easing' "element '43. is' disposedbelow the dial plate 33 and secured 'to the standard by" the screw 26',while; the arm 4570f: the'irel'easing element 43. is disposed above thedial plate 33iandtprovided with an upwardly turhed outer end: 146overhanging the annular row"-of digit k'eys- IK, etc;*lvl'ori-i'particularly, the. upwardly; turned outer" end 46 provided on the?arr'rr45 or: theireleasing'ielement 43 1 overhangs thefannul'ar, row ofi releasing tabs 4| .carried. by the-rocking bars36 hi the digit keys|K,.etc.r The arirr 45 63? the releasing element 43 is space'd'abovethe-upper surface of the dial plate 3 3 a distance suificient t6thefdepr'essed "releasing tabs 4| carried by the rocking bgfrs" 36"ofthe various digit keys IK', etc., to pass thereunden'incident tdrotationof the'dial plate 33', withoutengagehihtctherwit h w ger;"this; spacingor the upper surface of the dial plate 33 is such that an elevatedreleasing tab 4| carried by a, rocking bar 36 of any one of the digitkeys IK, etc., will engage the upwardly turned outer end 46 of the arm45, whereby the elevated releasing tab 4| carried by the rocking bar 36of the digit key IK, etc., is depressed.

The finger wheel |3 of the call transmitter H has arnormal position andis adapted to be variably rotat'editherefrom" in a clockwise direction,as Viewed'in Figs. 1 and 2; iii accordance with the difierent digits tobe transmitted, Subsequently, when the finger wheel I 3 of the calltransmitter II is released it is rotated in a counterclockwisedirection, as viewed in Figs. 1 and 2, back into its normal position bythe usual spring motor; whereby the impulse transmittingmechanism"hou'sed in the casing I2 of the call transmitter transmits acorresponding number of impulses in accordance with conventionalpractice! The dial plate "3'3 'has'a normal "pa e tioiiand' is variablyrotatabl' mar position in "the 01cc wi direction as v ewed in'Eig's.1"and2, hr aeeerda e with'fthediffei'ent digits to Poe transmittediri'fview' of the fact that thedia l plate 33 isdir'ectly andri'gidlygeeureatt the finger wheel whr' the call 'tiahsmitter r by the bracket23. When the control switch 23 i'sactuated'to"closetheoperatingbirc-liit the electric 'ino'tor'. 22 the "meter 22'bp'erates in" order to cause the operatingishaft 25 andifonsequ" litthe gear 351 to herctatuctntih ofislyfin clockwise direction, asviewed-"in Figs'fl and- "2; this operation of theelec'tric motor-f 21an'd'tlie' consequent rotation "ot the operating shaft 25 and the gear,35. earriedi'thereby continuing long as the operating circuit ot tlieelectricnib'toi 22. is completed. b'ythe actuated 'position of thecontrolswitcli 23." I

Considering now the operation of -the unit 20 in; conjunction with] thecall transmitter ll t'o transmit one or more digits from the telephonestation provided with; theftelephone set lathe operatonfii'st actuatesthe control-switch in order? to initiatev operationv of :the electricmotor 2212\nd. the consequent rotation oi the operating shaft 25 thereofand thei'gea'r 35 carried thereby," in the clockwise. direction,asviewe'd; in- 1 and: 2. r The operator thfen. effe c ts the trans:mission of the first digit;bydpfesSihgthelevatedu'operatingtab.4BL'carried b-y the rocking bar. steer the ap'propriatewdigit key Ire,etc. when the elevated operating tabjtl carried by the rockingi-bar 35.of the appropriate key-1K; eta, is thus depress-ed the releasing tabMcarrier; by the rocking bar SBQthereof elevated and etoggleiarmmlther'eo'f is oscillatedhbout itipivot in order. toirnbve theassociated=projectibn 425mg engagement." with. the teeth ofthecon'staiitly: tatin'fg gear: 351,4 whereby: the dial plat: elutchedtolthe gear '35 bytlieappropriate d -1 he 1K; "etc'l, mentioned! At thistime," t e, dial" plate 33; being clutched to the gea'r'35fis rarefied;in the. clockwise diibti'ofi' therewith away from its normal positiorLAlsof'the finger whel li-l or the, callfti'ansfnitte'ifl i's'ro teaa a'leckw-ise direction away from its'norrnal positiori, tdgether" withthedial p1ate'3'3, 'du'b' ta thiigid' ddhfle tioifcom'prisingthe"bTaCKet 'ZB Xtendingi twenrt'h'e finge'r eerlge"herthejeial platee iThe dial i la'te 33 'is rot 'edfiif direction;a'predetermine W norin theoperated dig1t{key' |=K- with H, the" other 'digit' k'eys in the"aml'illafr row? where -to transmit corresponding digits.

upon'the elevated releasing tab 4| carried by the rocking bar 36 of theoperated digit key IK, etc., engages the upwardly'turned outer end' lficarried by the arm 45 of' the releasing element and is depressed, aspreviouslyexplained. When the elevated releasing tab 4| carried by therocking bar 35 of the operated digit key IK, etc., is thus depressed theoperating tab 40 carried by the rocking bar 35 thereof is elevated andthe toggle arm 39 thereof is oscillated about its pivot in order to movethe projection 42 out of engagement with the teeth provided on theperiphery of the gear 35. Hence, the dial plate 33 is declutched fromthe gear 35 in order to permit free rotation of the continuouslyrotating gear 35 with respect to the dial plate 33 at this time. Whenthe dial plate 33 and the finger wheel l3 of the call transmitter I Iare thus rotated in the clockwise direction, as viewed in Figs. 1 and 2,the mechanism housed in the casing l2 of the call transmitter H is setto transmit a corresponding digit and the spring motor housed therein iswound. At this time the spring motor housed in the casing l2 of the calltransmitter ll returns the finger wheel 13 thereof and consequently thedial plate 33 in the counterclockwise direction, as viewed in Figs. 1and 2, back into their normal positions. When the finger wheel l3 of thecall transmitter H is returned in the counterclockwise direction backinto its normal position the impulse transmitting mechanism housed inthe casing l2 thereof operates to transmit the corresponding digit. Atthis time the elements of the call transmitter l l and the unit occupytheir normal positions; accordingly, another one of the digit keys IK,etc., may be operated in accordance with the second digit to betransmitted from the telephone station.

In view of the foregoing explanation of the mode of operation of theunit 20 in conjunction with the call transmitter l I, it will be readilyunderstood that each time one of the digit keys IK, etc., carried by thedial plate 33 is operated the unit 20 operates in order to efiectoperation of the call transmitter H to transmit the corresponding digit;and that, by repeatedly operating the various digit keys IK, etc.,carried by the dial plate 33, the unit 20 may be selectively controlledto govern the operation of the call transmitter l l to transmit a seriesof digits comprising the directory number of a called telephone station.

While one embodiment of the invention has been disclosed, it will beunderstood that various modifications may be made therein which arewithin the true spirit and scope of the invention.

What is claimed is:

l. A unit for operating the finger wheel of a call transmitter supportedby a telephone set; said unit comprising a support adapted to be securedto the telephone set, a member adapted to be secured to the finger wheelof the call transmitter, a set of digit keys movable with said-member, amotor, and means selectively controllable by said digit keys forimpartin variable rotation to said member from said motor, whereby thefinger wheel of the call transmitter is selectively rotated inaccordance with the operation of said digit keys in order to cause thecall transmitter 2. A unit for operating the finger Wheel of a calltransmitter; said unit comprising a member adapted to be secured to thefinger wheel of the call transmitter, a set of digit keys movable withsaid member, a motor, and means selectively controllable by saiddigitkeys for imparting variable rotation' to said member from said motor,whereby the finger wheel of the call transmitter is selectively rotatedin accordance with the operation of said digit keys in order to. causethe call transmitter to transmit corresponding digits.

3. In a call transmitter, a first rotatably mounted member biased to anormal position and variably rotatable away from its normal position inaccordance with different digits to be transmitted, a second rotatablymounted member, a motor for rotating said second member, a set ofmanually operable digit keys, means responsive to the operation of anyone of said digit keys {or restraining operated said one digit key andfor clutching said first member to said second member together forcontinuous rotation, whereby said first member is rotated away from itsnormal position, means responsive to the rotation of said first memberaway from its normal position an amount corresponding to said one digitkey for releasing said one digit key, means responsive to the release ofsaid one digit key for declutching said first member from said secondmember, whereby said first member is rotated back to its normalposition, and digit transmitting means operated by the rotation of saidfirst member for transmitting a digit corresponding to said one digitkey.

4. In a call transmitter, a first rotatably mounted member biased to anormal position and variably rotatable away from its normal position inaccordance with difierent digits to be transmitted, a second rotatablymounted member, a motor for rotating said second member, a set ofmanually operable digit keys disposed in a row and carried by said firstmember, means responsive to the operation of any oneoi said digit keysfor restraining operated said one digit key and 40 for clutching saidfirst member to said second member, whereby said first member is rotatedaway from its normal position, a release element, said digit keys in therow being brought successively adjacent to said release element as saidfirst member is rotated away from its normal position, means includingsaid release element for rel sin said one digit key when it is broughtadjacent thereto, means responsive to the release of said one digit keyfor declutching said first member from said second member, whereby saidfirst member is rotated back to its normal position, and digittransmitting means operated by the rotation of said first member fortransmitting a digit corresponding to said one digit key.

5. In a call transmitter, a first rotatably mounted member biased to anormal position and variably rotatable away from its normal position inaccordance with different digits to be trans mitted, a second rotatablymounted member, a motor for rotating said second member, a set ofmanually operable digit keys disposed in a row and carried by said firstmember, each of said digit keys being of the rocking-bar type includingan operating projection and a releasing projection, means controlledwhen the operating projection of any one of said digit keys is depressedfor restraining depressed the operating projection thereof and forelevating the releasing projection thereof, means responsive to thedepression of the operating projection of said one digit key forclutching said first member to said second member, whereby said firstmember is rotated away from its normal position, a release element, therelease projections of said digit keys in the row being broughtsuccessively adjacent to said release element-as said first member is"rotated away from its normal position, whereby the elevated releasingrojection of said one digit key is brou ht into engagement with saidrelease element and depressed thereby, means responsive to thedepression of the releasing projection of said one digit key forelevating the operating projection thereofimeans responsive to theelevation of the operating projection of said one digit key for,declutching said first member from said second member, whereby saidfirst member is rota ted back to its normal position; and digittransmitting means operated by the rotation of said first member fortransmitting a digit corresponding to said one digit key. t

6. A unit for operating the finger wheel of a call transmitter supportedby atelephone set; said unit comprising a support adapted to be securedto the telephone set, a member adapted to be secured to the finger wheelof the 'call transmitter to rotate therewith, a set of digit keysmounted in anjanniilar' series to rotate with said member, a motor, arotar member adapted tobe rotated continuously by said motor, and meansselectively controllable by'said digit keys forselectively formingdriving connections be tween saidmembers' to cause variable degrees ofrotation of said first-named member depend ingjupon the position of theoperated digit key. '7; In acall transmitter, a finger wheel biasedtoanormal position and variably rotatable away from that position in.accordance with diiferent digits to be transmitted, a second rotatablymounted member, a motor for rotating said last-- named member, a set ofmanually operated digit keys movable with said finger wheel, means responsive to the operation of any one of said digit keys for establishinga driving connection to cause said finger wheel to rotate to an extentdetermined by the position of the operated digit key. r p

a 7 RALPH CROCKER;

